Collar bearing split shell and collar bearing with a centering device, and corresponding thrust washer

ABSTRACT

The invention relates to a collar bearing split shell ( 1′, 1″ ), comprising a bearing shell ( 2, 2′, 2″ ) and two thrust washers ( 3, 3   a′   , 3   b′,    3   c′,    3   d ′) which are located on said bearing shell ( 2, 2′, 2″ ). The invention also relates to a collar bearing ( 1 ) comprising two collar bearing split shells ( 1′, 1″ ), each of which has a bearing shell ( 2, 2′, 2″ ), at least one bearing shell ( 2, 2′, 2″ ) being provided with two thrust washers ( 3, 3   a′,    3   b′,    3   c′,    3   d′ ) located on said bearing shell ( 2, 2′, 2″ ). The invention also relates to a thrust washer ( 3   a′ ) for a collar bearing split shell ( 1′ ). The aim of the invention is to provide a collar bearing ( 1 ) which ensures that the two collar bearing split shells ( 1′, 1″ ) of a collar bearing ( 1 ) are essentially flush with each other when installed. To this end, the invention provides for a collar bearing split shell on which the ends ( 7, 7′, 7″ ) of the two thrust washers ( 3, 3   a,    3   b,    3   c,    3   d ) of the bearing shell ( 2, 2′, 2″ ) extend at least partially beyond the semi-circle-shaped bearing shell ( 2, 2′, 2″ ) in the peripheral direction; or a generic collar bearing ( 1 ) on which the ends ( 7, 7′, 7″ ) of the two thrust washers ( 3, 3   a′,    3   b′,    3   c′,    3   d′ ) of at least one bearing shell ( 2, 2′, 2″ ) extend at least partially beyond the semi-circle-shaped bearing shell ( 2, 2′, 2″ ) in the peripheral direction. A thrust washer ( 3   a ) which is configured as a ring segment and which extends through an angle of more than 180° and a bearing shell, forming a combined collar bearing ( 1 ), also solve the problem addressed by the invention.

[0001] The invention relates to a flange bearing half shell having abearing shell and two thrust washers arranged on said bearing shell.

[0002] The invention also relates to a flange bearing having two flangebearing half shells, each of which comprises a bearing shell, at leastone bearing shell having two thrust washers arranged on said bearingshell.

[0003] The invention also relates to a thrust washer for a flangebearing half shell, which takes the form of a ring segment.

[0004] Such flange bearings are used for example in internal combustionengines for bearing-assisted mounting of the crankshaft in thecrankcase. Due to the right-angle bends in the crankshaft, the flangebearings are in principle constructed in two parts, in the form of twoflange bearing half shells, with a view to facilitating mounting.Crankshafts of dismantable modular construction are also to be found,which allow the use of one-part flange bearings, but these are stillvery much the exception in mass production, in particular due to thehigh manufacturing costs.

[0005] The bearing shell serves to absorb radial bearing forces, whichare introduced via the shaft rotating in the bearing shell, whereas thethrust washer, of which there is at least one, serves to absorb axialforces. If there is a need to absorb axial forces in both directions ofthe shaft, two thrust washers have to be provided, since each thrustwasher is only in a position to absorb the forces directed towards itsoverlay.

[0006] Cheeks are provided on the shaft, by means of which the shaft issupported on the thrust washer.

[0007] As a rule, the crankshaft bearing arrangement comprises aplurality of radial plain bearings, i.e. a plurality of bearings withoutthrust washers, and one combined radial/axial plain bearing. Thisradial/axial plain bearing has the thrust washers necessary forabsorbing axial forces. Reference is made below to the combinedradial/axial plain bearing, since it is this plain bearing constructionwhich substantially constitutes the subject matter of the invention.

[0008] The flange bearings conventionally constructed in two parts inthe form of two flange bearing half shells are preliminarily mounted insuch a way in the crankcase that, prior to insertion of the crankshaft,the upper flange bearing half shell is positioned in the upper half ofthe crankcase and the lower flange bearing half shell is positioned inthe lower half, or “cover”, of the crankcase.

[0009] The upper half of the crankcase is the part of the crankcasewhich is connected with the engine block, i.e. the part of the crankcasewhich is arranged between the crankcase, essentially a casting, which isport-machined and comprises a bearing saddle for accommodating the upperflange bearing half shell, onto which the upper flange bearing halfshell is fitted during mounting.

[0010] As a rule, the upper flange bearing half shell has a hole,through which the plain bearing is supplied with oil. The oil itself isfed as far as into the bearing saddles of the crankcase by means of feedlines. Consequently, care must be taken when fitting the upper flangebearing half shell to ensure that the oil supply hole in the bearingshell is aligned with the outlet of the oil supply line in the bearingsaddle. A central and thus symmetrical arrangement of the hole is notexpedient, since the supply hole has as a rule to be arrangedeccentrically due to pressure distribution in the plain bearinglubricating oil film. Incorrect positioning of the upper flange bearinghalf shell in the bearing saddle and thus closure of the oil supply lineresults in inadequate oil supply to the plain bearing and, in the worstcase scenario, to dry running of the bearing and bearing destruction.

[0011] For this reason, mounting aids are provided to assist inmounting. It is usual in practice to arrange a lug-type, outwardlyprojecting cam on the outer circumferential surface of the bearingshell, wherein a recess corresponding to said cam is provided in thebearing saddle of the crankcase. The flange bearing half shell, with itsoutwardly projecting cam, can then only be properly mounted in thebearing block when cam and recess fit together, i.e. the oil supply holeof the bearing shell is aligned with the outlet opening of the oilsupply line in the bearing saddle and the flange bearing half shell iscorrectly oriented.

[0012] Constructing the mounting aid as a cam and corresponding recessis complex, due to the manufacturing process which has to be carriedout, and requires a plurality of operations. The outwardly projectingcam is generated by a stamping process. The plain bearing material whichis detached from the bearing shell in the process has to be carefullyremoved, so that loose particles do not become the cause of bearingfretting after mounting and during operation of the internal combustionengine.

[0013] Apart from the absent oil supply hole, the lower flange bearinghalf shell is of the same construction as the upper flange bearing halfshell. It too has a cam as mounting aid.

[0014] The lower half shell of the flange bearing is arranged in thecrankcase cover. To this end, the bearing cover is provided in the casecover to accommodate the lower flange bearing half shell. Together withthe bearing saddle arranged in the upper case part, the bearing coverforms the receptacle for the flanged bearing, wherein the bearing saddleaccommodates the upper flanged bearing half shell and the bearing coverthe lower flanged bearing half shell.

[0015] After preliminary mounting, i.e. fitting the two flange bearinghalf shells into the upper case part and the case cover respectively andcarrying out the remaining preliminary operations, the upper case partis fitted together with the case cover and screwed thereto, so as thusto form a closed crankcase.

[0016] The two crankcase parts do not as a rule have any centeringdevices which fixedly determine the relative position of these twocomponents to one another. The screw connections provided in thecrankcase, which connect the case cover firmly to the upper case part,by their nature exhibit a clearance and cannot for this reason serve ascentering devices, such that the case cover may be moved, in particularby up to a few tenths of a millimeter in the direction of the crankshaftaxis, relative to the upper case part once the screws have been screwedin but not tightened.

[0017] The two-part crankcase consisting of the upper case part and thecase cover is generally divided along a straight line, i.e. the bearingcover and the bearing saddle, which together form the receptacle for theflange bearing, each have a semicircular recess extending over an angleof 180°, into which the flange baring half shells may be inserted. Theseflange bearing half shells are likewise generally divided along astraight line and extend over an angle of 180°.

[0018] If, as already explained, the case cover is displaceable anduncentered relative to the upper case part in the direction of thecrankshaft axis due to the lack of a centering device, the lower flangebearing half shell may also be displaced relative to the upper flangebearing half shell. Neither of the two flange bearing half shells ispurposefully oriented and fixed with regard to the flange baring halfshell opposite it.

[0019] If the two flange bearing half shells are axially offset, the twothrust washers arranged to the left of the bearing bore or to the rightof the bearing bore do not lie in a plane, such that on the one hand thebearing absorbs forces or fulfills its task of providing axial guidanceand support for the crankshaft only on the thrust washer which protrudesfurther axially. On the other hand, overloading of the only partiallystressed bearing may occur.

[0020] Against this background, it is the object of the presentinvention to provide a measure which ensures that the two flange bearinghalf shells of a flange bearing are aligned with one another when fittedand to provide a device with which the crankcase cover is centered inthe upper part of the crankcase.

[0021] This object is achieved by a flange bearing half shell having abearing shell and two thrust washers arranged on said bearing shell, theends of the two thrust washers of the bearing shell extendingcircumferentially at least in part beyond the semicircular bearingshell.

[0022] This object is also achieved by a flange bearing having twoflange bearing half shells, of which each comprises a bearing shell andat least one baring shell has two thrust washers arranged on saidbearing shell, the flange bearing being characterized in that the endsof the two thrust washers of at least one bearing shell extendcircumferentially at least in part beyond the semicircular bearingshell.

[0023] Embodiments which are favored are those in which the thrustwashers are welded to the bearing shell.

[0024] Because the ends of the thrust washers of at least one bearingshell extend circumferentially beyond the semicircular bearing shell, aflange bearing half shell arranged in one crankcase part engages withits thrust washers in the opposing crankcase part.

[0025] For example, a flange baring half shell arranged in the uppercase part engages with its thrust washers, formed according to theinvention, in the manner of fingers in the case cover. In this way, theflange bearing half shell itself is virtually fixed in the axialdirection by the bearing saddle arranged in the upper case part, whereina clearance fit is selected as a rule for the bearing half shell/bearingsaddle combination, in such a way that the baring saddle accommodatedbetween the thrust washers of the bearing half shell may still be movedmanually, i.e. a clearance is present between the bearing saddle and thethrust washers accommodating it of for example 20 μm to 50 μm.

[0026] The ends of the thrust washers formed according to the inventionof said flange bearing half shell accommodated by the bearing saddleengage in the case cover and fix the bearing cover arranged in the casecover between them. In this way, the cover of the crankcase, connectedrigidly with the bearing cover, is likewise fixed. The neighboring endsof the opposing thrust washers engage in each case to the right and leftof the actual bearing bore or of the crankshaft axis in the manner of afork in the bearing block or bearing cover and thus fix the bearingblock or a wall belonging to the bearing block.

[0027] The bearing cover exhibits, with regard to the two thrust washersarranged to the right and left thereof, a manufacturing tolerance whichresults in a clearance fit for the bearing half shell/bearing saddlecombination, as already explained with reference to the bearing saddle.Between the bearing cover and the thrust washers bounding it to theright and left, a slight clearance is established, for example, which isof the order of from 20 μm to 50 μm, for example.

[0028] Due to the flange bearing according to the invention, in whichthe ends of the two thrust washers of a least one bearing shell extendcircumferentially at least in part beyond the semicircular bearingshell, sufficiently precise centering of the case cover on the upperpart of the crankcase is achieved with simple means, wherein a toleranceis achieved with amounts, in the above-mentioned numerical example, tofrom 20 μm to 50 μm for example, i.e. the case cover is fixed on theupper case part with a maximum axial deviation of 50 μm form apredetermined nominal position.

[0029] The explanations given for the upper flange bearing half shellapply in the same way to the lower flange bearing half shell, whereinthis bearing half shell is then seated in the lower case part and fixesthe bearing saddles between its thrust washers in the manner of a forkand thus centers the upper case part relative to the lower case part.

[0030] The flange bearing according to the invention renders itunnecessary to provide additional means forming a centering device, butinstead used components already present for this purpose, by furtherdeveloping in accordance with the invention a thrust washer known perse. Thus, there are no additional parts to be mounted during mountingand in principle no additional parts have to be held in stock duringmanufacture, such that production, in particular mounting, becomesneither more complex nor more cost-intensive while at the same time thequality of the internal combustion engine produced is improved.

[0031] The flange bearing according to the invention on the one handallows centering of the case cover on the upper case part. On the otherhand, it is ensured that the two bearing half shells are aligned withone another when fitted.

[0032] The disadvantages known from the prior art, which appear when acentering device for the two crankcase parts is absent, may beeliminated or reduced. The thrust washers of the mutually opposingbearing shells are each aligned with one another, i.e. the two thrustwashers arranged axially to the right of the flange bearing and to theleft of the flange bearing respectively lie with their running surfacesapproximately in a plane.

[0033] Flange bearings are advantageous, in which only the ends of thetwo thrust washers of one bearing shell extend circumferentially atleast in part beyond the semicircular bearing shell.

[0034] An advantage of this embodiment of the flange bearing is thatcentering of the two crankcase parts is effected by only one bearingshell, such that the second bearing shell, which is opposite thecentering bearing shell, does not have to be constructed with regard tothe object to be achieved, i.e. with regard to centering.

[0035] Consequently, the second bearing shell may be a bearing shellaccording to the prior art, provided it is constructed in such a waythat, together with the flange bearing half shell constructed accordingto the invention, it may form a flange bearing. In particular, it ispossible to provide a bearing shell without thrust washers as a secondbearing shell. The thrust washers of the centering bearing shellpreferably extend as far as possible in the circumferential direction,in order to produce the largest possible sliding surface for the axialplain bearing. The only limit thereto is that the crankshaft has stillto be incorporated or inserted, as a function of its crankshaftdiameter, into the centering bearing shell thus constructed.

[0036] Embodiments of the flange bearing are also advantageous, in whichthe ends of the two thrust washers of both bearing shells extendcircumferentially at least in part beyond the semicircular bearingshell.

[0037] An advantage of this embodiment is that the thrust washers ofboth bearing shells then form the centering device and together centerthe crankcase upper part and cover. In this way, it is possible toprovide a sliding surface for the axial plain bearing which is virtuallycontinuous over 360°. The thus maximized running surface of the axialplain bearing then leads, given equal axial loading, to lower specificsurface pressure.

[0038] This embodiment has the additional advantage that the axialforces which may be exerted on the centering device by the assembledcrankcase parts are distributed over more thrust washers.

[0039] Embodiments of the flange bearing are advantageous in which atleast a first end of a thrust washer of a first bearing shell comprisesfirst mounting aids and a second end of a thrust washer of a secondbearing shell, which is opposite and in engagement with the first endwhen the flange bearing is assembled, has mounting aids complementary tothe first mounting aids, in such a manner that the flange bearing canonly be assembled if the flange baring half shells are oriented asrequired for fitting.

[0040] A favorable feature of this embodiment is that, by means ofmounting means provided, which are components of the flange bearing halfshells themselves, it may be clearly determined whether the two bearingshells are correctly positioned relative to one another. Consequently,proper mounting of one bearing half shell is sufficient, wherein thismounted baring half shell creates a framework for mounting of the secondbearing half shell still to be mounted, i.e. the two bearing half shellscan only be assembled in a given arrangement due to the mounting aidsprovided.

[0041] Consequently, it is possible to omit provision on the secondbearing half shell of aids which serve, independently of the firstbearing half shell, as an indicator for the correct positioning of thesecond bearing half shell. It is a widespread practice, as alreadystated with reference to the prior art, to provide an outwardlyprojecting cam, which is arranged on the outer circumferential surfaceof the bearing half shell and engages in the mounted state in a recessin the bearing bore corresponding to the cam.

[0042] Provision of such a cam on the second bearing shell is no longernecessary due to the integral mounting aids, thereby reducing costs inparticular.

[0043] Embodiments of the flange bearing are advantageous in which themounting aids take the form of bevels. These mounting aids may be simplyproduced, beveling of the ends of the thrust washers sometimes beingeffected even in the case of flange bearings according to the prior art,but without constructing and using the bevels as mounting aids for thepurposes of the present invention.

[0044] Embodiments of the flange bearing are advantageous in which thebevels are formed in such a manner that the internal radius or externalradius of the thrust washer changes continuously in the circumferentialdirection. In this case, the thrust washer tapers towards its end, thethickness of the thrust washer preferably remaining the same.

[0045] Embodiments of the flange bearing are advantageous in which thebevels are formed in such a manner that the thickness of the thrustwasher changes continuously in the circumferential direction towards theend of the thrust washer. Then, both the inner surface of the thrustwasher may remain unchanged and the thickness start to reduce at theouter surface, and the outer surface of the thrust washer may remainunchanged and the thickness start to reduce at the inner surface.

[0046] Embodiments of the flange bearing are advantageous, in which themounting aids are identical on one side of each bearing shell and differfrom the mounting aids on the other side of said bearing shell. Thismeasure ensures that a bearing shell rotated by 180° from the mountingposition cannot be joined to the opposing, correctly oriented bearingshell.

[0047] Embodiments of the flange bearing are favorable in which at leastone thrust washer has an outwardly projecting lug located in the planeof the thrust washer.

[0048] One of the two flange bearing half shells is preferably providedwith an aid which ensures correct orientation of said bearing shell uponfitting. In contrast to the bearing shells according to the prior art,which conventionally provide a cam on the bearing shell and a recess inthe bearing bore, which engage in one another in the assembled state, inthe case of the flange bearing according to the invention a fitting aidis provided in the form of an outwardly projecting lug arranged on athrust washer.

[0049] To accommodate this lug, a recess for accommodating this lug ispreferably included as early as in the structural design of thecrankcase, such that this recess is generally already a component of thecase crankcase.

[0050] Embodiments of the flange bearing are advantageous in which thethrust washer, of which there is at least one, comprises grooves at itsouter surface, which grooves intersect with the outer surface in themanner of a secant. These grooves are necessary to form a load-bearinglubricant film on the thrust washer and to remove oil.

[0051] The scope of protection of the present invention also covers athrust washer for a flange bearing half shell which takes the form of aring segment and is characterized in that it extends over an angle ofmore than 180°. Together with a corresponding bearing shell, a pair ofsuch thrust washers achieves, as a combined flange bearing, the objectforming the basis of the invention. The particular structuralconfiguration of the thrust washer according to the invention should bedeemed the nub of the present invention.

[0052] Embodiments of the thrust washer are advantageous which have anoutwardly projecting lug located in the plane of the thrust washer.

[0053] The invention is explained more fully below with reference to twoexemplary embodiments according to FIGS. 1 and 2, in which:

[0054]FIG. 1 is a perspective representation of a first embodiment of aflange bearing half shell, and

[0055]FIG. 2 is a perspective representation of a second embodiment of aflange bearing with the two flange bearing half shells forming theflange bearing.

[0056]FIG. 1 is a perspective representation of a first embodiment of aflange baring half shell 1′. The flange bearing half shell 1′ has abearing shell 2 and two thrust washers 3 arranged on said bearing shell2. The thrust washers 3 are welded to the outer circumferential surfaceof the bearing shell 2 in such a manner that the thrust washers 3 areideally perpendicular to the axis of the flange bearing or perpendicularto the axis of the crankshaft to be borne by the flange bearing. Thethrust washers 3 are arranged at the edges or end faces of the bearingshell 2. Clearly recognizable is the weld seam 8, by means of which thefront thrust washer 3 is connected with the bearing shell 2.

[0057] The four ends 7 of the two thrust washers 3 extendcircumferentially beyond the semicircular bearing shell 2. Theneighboring ends 7 of the opposing thrust washers 3 each form a type offork. If the flange bearing half shell 1′ illustrated in FIG. 1. whichdoes not comprise an oil supply hole and is provided for arrangement inthe cover of the crankcase, is then mounted in a bearing cover arrangedin the case cover, the ends 7 of the thrust washers 3 engage in theupper part of the crankcase when the crankcase is in the assembledstate. The fork-like ends 7 of the thrust washers 3 then engage in thebearing saddle, on which the opposing flange bearing half shell 1″ (notshown) is placed, wherein the bearing saddle or a wall belonging to thebearing saddle is fixed between the thrust washers 3, thereby achievingcentering of the two crankcase parts relative to one another.

[0058] A flange bearing using the flange bearing half shell 1′illustrated in FIG. 1 effects centering of the two crankcase parts withonly one flange bearing half shell 1′, namely the one illustrated. Asecond bearing shell, lying opposite the centering flange bearing halfshell 1′, may be a bearing shell constructed according to the prior art,provided that it is so constructed that it may form a flange bearingtogether with the flange bearing half shell 1′ constructed according tothe invention. In particular, it is possible to provide a bearing shellwithout thrust washers as a second bearing shell, since the flangebearing half shell 1′ illustrated has large-area thrust washers 3. Thesethrust washers 3 form an outer surface 9, which by itself forms asufficiently large plain bearing surface without the addition of afurther thrust washer of a second bearing shell. The outer surfaces 9 ofthe thrust washers 3 have two grooves 5, which intersect with the outersurfaces 9 in the manner of a secant. These grooves 5 are necessary tobuild up a sufficiently load-bearing lubricant film in the axial plainbearing and to remove oil.

[0059] The flange bearing half shell 1′ shown in FIG. 1 additionally hasa groove 6 arranged in the running surface of the bearing shell 2. Thisgroove 6 extends circumferentially, i.e. in the direction of rotation ofthe crankshaft, and serves as an oil reservoir for accommodatinglubricating oil.

[0060] Furthermore, the bearing shell 2 comprises at its edgescircumferentially extending grooves 4, which increase the flexibility ofthe bearing shell 2 and thus of the entire flange bearing half shell 1′.

[0061]FIG. 2 shows an embodiment of the flange bearing 1 in which thetwo bearing shells 2′, 2″ each have two thrust washers 3 a′, 3 b′, 3 a″,3 b″.

[0062] The upper flange bearing half shell 1′ is illustrated in explodedperspective view, with thrust washers 3 a′, 3 b′ not attached to thebearing shell 2′. The lower flange bearing half shell 1″ is illustratedin the assembled state as a finished component.

[0063] This lower flange bearing half shell 1″ is very similar to theflange bearing half shell illustrated in FIG. 1. Its thrust washers 3a″, 3 b″ are arranged on the outer circumferential surface of thebearing shell and connected undetachably via a weld seam 8 to thebearing shell 2″. Again, they are perpendicular to the flange bearingaxis and are arranged at the end faces of the bearing shell 2″.

[0064] The ends 7″ of the thrust washers 3 a″, 3 b″ extendcircumferentially, but only in part beyond the semicircular bearingshell. In addition, the ends 7″ of these two thrust washers 3 a″, 3 b″comprise mounting aids 7 a″, 7 b″, 7 c″, 7 c″ in the form of beveledends 7″ of the thrust washers 3 a″, 3 b″.

[0065] In the embodiment of the flange bearing 1 illustrated in FIG. 2,the upper flange bearing half shell 1′ is constructed like the lowerflange bearing half shell 1″ except for two structural elements.

[0066] One further structural element, which the upper flange bearinghalf shell 1″ comprises in contrast to the lower flange bearing halfshell 1″, is the oil supply hole 11 arranged eccentrically in thebearing shell 2′, via which hole 11 the flange bearing 1 is suppliedwith lubricating oil. The oil supply hole 11 has to be aligned with theoutlet of the oil supply line in the bearing bore, such that the upperflange bearing half shell 1′ cannot be mounted in just any way on thebearing saddle arranged in the upper crankcase part.

[0067] An outwardly projecting lug 10 located in the plane of the thrustwasher is arranged on the front thrust washer 3 a′ as a mounting aid formounting the upper flange bearing half shell 1′. When the flange bearinghalf shell 1′ is correctly positioned, this lug 10 engages in a recesscorresponding thereto, which is to be provided on the bearing receptacleor the bearing saddle in the crankcase. This lug ensures that the upperflange bearing half shell 1′ can only be mounted in a predeterminedposition.

[0068] The ends 7′ of the thrust washers 3 a′, 3 b′ of the upper flangebearing half shell 1′ comprise first mounting aids 7 a′, 7 b′, 7 c′, 7d′, which engage, when the flange bearing 1 is assembled, with themounting aids 7 a″, 7 b″, 7 c″, 7 d″ arranged at the ends 7″ of thethrust washers 3 a″, 3 b″ of the lower flange bearing half shell 1′.

[0069] The mounting aids 7 a′, 7 b′, 7 c′, 7 d′ of the upper bearinghalf shell 1′ likewise take the form of bevels. As in the case of thelower flange bearing half shell 1″, the bevels on one side of thebearing shell 2′, 2″ are oriented in the same way, i.e. identically, anddifferently from the bevels on the other side of said bearing shell 2′,2″.

[0070] The bevels are formed in such a manner that the internal radiusor external radius of the thrust washer 3 a′, 3 b′, 3 a″, 3 b″ changescontinuously in the circumferential direction. The thrust washers 3 a′,3 b′, 3 a″, 3 b″ taper towards their ends 7′, 7″, wherein the thicknessof the thrust washers 3 a′, 3 b′, 3 a″, 3 b″ preferably remains thesame.

[0071] The upper flange bearing half shell 1′ inserted into the upperhalf of the crankcase creates a framework, so to speak, for fitting ofthe lower flange bearing half shell 1″. According to the invention, thetwo flange bearing half shells 1′, 1″ may only be assembled into aflange bearing 1 if the flange bearing half shells 1′, 1″ are orientedcorrectly for fitting. Then, the first mounting aids 7 a′, 7 b′, 7 c′, 7d′ of the upper flange bearing half shell 1′ cooperate with the secondmounting aids 7 a″, 7 b″, 7 c″, 7 d″ of the lower flange bearing halfshell 1″ in accordance with the “key and lock” principle. Since themounting position of the lower flange bearing half shell 1″ ispredetermined by the opposing upper flange bearing half shell 1′, afurther mounting aid in the form of a lug or a cam to be arranged on thebearing shell may be dispensed with.

[0072] The thrust washers 3 a′, 3 b′, 3 a″, 3 b″ each have two grooves 5in their outer surfaces 9, which grooves 5 are required to form aload-bearing lubricant film.

[0073] In the case of the flange bearing 1 illustrated in FIG. 2,centering of the two crankcase parts relative to one another is effectedvia two flange bearing half shells 1′, 1″. With the ends 7′ of the twothrust washers 3 a′, 3 b′, which extend circumferentially at least inpart beyond the semicircular bearing shell 2′, the upper flange bearinghalf shell 1′ arranged in the upper case part centers the case coverrelative to the upper crankcase part.

[0074] On the other hand, the lower flange bearing half shell 1″arranged in the case cover uses the ends 7″ of its two thrust washers 3a″, 3 b″, which extend circumferentially at least in part beyond thesemicircular bearing shell 2″, to center the upper case part relative tothe case cover. The two flange bearing half shells 1′, 2′ jointly assumethe role of a centering device.

LIST OF REFERENCE NUMERALS

[0075]1 Flange bearing

[0076]1′ Flange bearing half shell

[0077]1″ Flange bearing half shell

[0078]2 Bearing shell

[0079]2′ Bearing shell

[0080]2″ Bearing shell

[0081]3 Thrust washer

[0082]3 a′ Thrust washer

[0083]3 b′ Thrust washer

[0084]3 a″ Thrust washer

[0085]3 b″ Thrust washer

[0086]4 Groove

[0087]5 Groove

[0088]6 Groove

[0089]7 End

[0090]7′ End

[0091]7″ End

[0092]7 a′ First mounting aid

[0093]7 b′ First mounting aid

[0094]7 c′ First mounting aid

[0095]7 d′ First mounting aid

[0096]7 a″ Second mounting aid

[0097]7 b″ Second mounting aid

[0098]7 c″ Second mounting aid

[0099]7 d″ Second mounting aid

[0100]8 Weld seam

[0101]9 Outer surface

[0102]10 Lug

[0103] Oil supply hole

1. A flange bearing half shell (1′, 1″) having a bearing shell (2, 2′,2″) and two thrust washers (3, 3 a′, 3 b′, 3 a″, 3 b″) arranged on saidbearing shell (2, 2′, 2″), characterized in that the ends (7, 7′, 7″) ofthe two thrust washers (3, 3 a′, 3 b′, 3 a″, 3 b″) of the bearing shell(2, 2′, 2″) extend circumferentially at least in part beyond thesemicircular bearing shell (2, 2′, 2″).
 2. A flange bearing (1) havingtwo flange bearing half shells (1′, 1″), each of which comprises abearing shell (2, 2′, 2″), at least one bearing shell (2, 2′, 2″) havingtwo thrust washers (3, 3 a′, 3 b′, 3 a″, 3 b″) arranged on said bearingshell (2, 2′, 2″), characterized in that the ends (7, 7′, 7″) of the twothrust washers (3, 3 a′, 3 b′, 3 a″, 3 b″) of at least one bearing shell(2, 2′, 2″) extend circumferentially at least in part beyond thesemicircular bearing shell (2, 2′, 2″).
 3. A flange bearing (1)according to claim 2, characterized in that only the ends (7) of the twothrust washers (3) of one bearing shell (2) extend circumferentially atleast in part beyond the semicircular bearing shell (2).
 4. A flangebearing (1) according to claim 2, characterized in that the ends (7, 7′,7″) of the two thrust washers (3, 3 a′, 3 b′, 3 a″, 3 b″) of bothbearing shells (2, 2′, 2″) extend circumferentially at least in partbeyond the semicircular bearing shell (2, 2′, 2″).
 5. A flange bearing(1) according to claim 4, characterized in that at least a first end(7′) of a thrust washer (3 a′, 3 b′) of a first bearing shell (2′)comprises first mounting aids (7 a′, 7 b′, 7 c′, 7 d′) and a second end(7″) of a thrust washer (3 a″, 3 b″) of a second bearing shell (2″),which is opposite and in engagement with the first end (7′) when theflange bearing (1) is assembled, has second mounting aids (7 a″, 7 b″, 7c″, 7 d″) complementary to the first mounting aids (7 a′, 7 b′, 7 c′, 7d′), in such a manner that the flange bearing (1) can only be assembledif the flange bearing half shells (1′, 1″) are oriented as required forfitting.
 6. A flange bearing (1) according to claim 5, characterized inthat the mounting aids (7, 7 a′, 7 b′, 7 c′, 7 d″, 7 a″, 7 b″, 7 c″, 7d″) take the form of bevels.
 7. A flange bearing (1) according to claim6, characterized in that the bevels are so constructed that the internalradius or external radius of the thrust washer (3, 3 a′, 3 b′, 3 a″, 3b″) changes continuously in the circumferential direction.
 8. A flangebearing (1) according to claim 5, characterized in that the mountingaids (7 a″, 7 b″) are identical on one side of each bearing shell (2′,2″) and differ from the mounting aids (7 c″, 7 d″) on the other side ofsaid bearing shell (2, 2″).
 9. A flange bearing (1) according to one ofclaims 2 to 8, characterized in that at least one thrust washer (3 a′)has an outwardly projecting lug (10) located in the place of the thrustwasher (3 a′).
 10. A thrust washer (3, 3 a′, 3 b′, 3 a″, 3 b″) for aflange bearing half shell (1′, 1″), which takes the form of a ringsegment, characterized in that it extends over an angle of more than180°.
 11. A thrust washer (3 a′) according to claim 10, characterized inthat it has an outwardly projecting lug (10) located in the plane of thethrust washer (3 a′).